Miniature axial bridging rotary switch with improved housing

ABSTRACT

Multi-position electrical switch including switch sections or decks arranged so that any desired number of sections can be used. Each section includes a rotor for selectively bridging switch contacts which can be arranged in different manners as required in different applications. A large number of switch positions, for example, 24, can be provided in a very small switch structure. The individual contacts for the different positions are embedded in a plastic insulating member to provide a solid insulated support therefor.

United States Patent. OMalley [54] MINIATURE AXIAL BRIDGING ROTARYSWITCH WITH IMPROVED HOUSING [72] Inventor: Thomas J. OMalley,Brookfield, Ill. [73] Assignee: Grayhill, Inc., La Grange, Ill.

[22] Filed: Feb. 1, 1971 [2]] Appl. Nd: 111,545

[52] US. Cl... ..200/ll A, ZOO/ll D, ZOO/l4 [5i] lnt.Cl ..H0lh 19/58,HOlh 2l/78 [58] Field ofSearch ..200/l l A, ll D, l4, 17 R, I685 [56]References Cited UNITED STATES PATENTS 3,588,392 6/1971 Cartwright..200/ll A June 6,1972

3,525,826 8/1970 Allison ..200/ll D 3,286,046 11/1966 Mincone ..200/l7RXPrimary Examiner-J. R. Scott Attorney-Mueller & Aichele [57] ABSTRACTMulti-position electrical switch including switch sections or decksarranged so that any desired number of sections can be used. Eachsection includes a rotor for selectively bridging switch contacts whichcan be arranged in different manners as required in differentapplications. A large number of switch positions, for example, 24, canbe provided in a very small switch structure. The individual contactsfor the different positions are embedded in a plastic insulating memberto provide a solid insulated support therefor.

l 1 Claims, 6 Drawing Figures PATENTEDJUN 6 I972 3.668 338 InventorTHOMAS J O'MALLEY ATTYS.

MINIATURE AXIAL BRIDGING ROTARY SWITCH WITH IMPROVED HOUSING BACKGROUNDOF THE INVENTION provides 12 switch positions, and it has also beenconstructed with switch positions.

There has been a significant demand for miniature rotary switches havingmore than 12 positions. More specifically, switches are required invarious applications which have 16, and 24 positions. The switches whichare available and which have such a large number of positions have beenquite large, substantially larger than the switches constructed inaccordance with US. Pat. No. 3,297,836. Although attempts have been madeto provide smaller switches with 16 or more positions, the switches havenot been entirely satisfactory in operation and have not been of aconstruction to provide the contact arrangements which are required inmany applications.

SUMMARY OF THE INVENTION It is, therefore, an object of the presentinvention to provide a miniature multi-position rotary switch which isof simple construction and which can have as many as 16 or more switchpositions.

Another object of the invention is to provide a multi-position rotaryswitch having a large number of switch positions, with the contactsrequired for such switch positions being embedded in closely spacedrelation in an insulating support housing, and insulated from each otherthereby. I

A further object of the invention is to provide a miniaturem'ulti-position rotary switch which has a plurality of switch sectionsor decks, with a common operator therefore and independent contactstructures, with each deck having a large number of switch positions.

In accordance with the invention, a miniature rotary electrical switchis provided including a base member to whicha rotary actuator isconnected, and which has a detent structure and a stop structure coupledthereto. One or more switch decks are connected to the'base member, withthe actuator extending through the switch decks to move the rotorsthereof. Each switch deck includes a cylindrical insulating housingsection having a plurality of conductors embedded therein at radiallyspaced positions. The conductors have portions extending outside thehousing forming terminals, and portions extending inside the housingforming switch contacts. A rotor within each housing section has one ormore contacts therein which selectively engage the contacts of theconductors embedded in the housing, and one or more other contactsprovided on a plate which closes one end of the housing section. Theother end of the housing section is closed by a disc having ridgesextending therefrom into the spaces between the switch contacts. Theridges insure that the contacts are insulated from each other and formrecesses or wells for receiving foreign particles, so that suchparticles are removed from the vicinity of the switch contacts. Theridges mayextend into the path of the moving contacts, and serve toclean such contacts as they move from one position to the other.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 6 illustrates a modification ofthe contact structure.

DETAILED DESCRIPTION In FIG. 1 there is shown a miniature multi-positionrotary switch of the invention which includes a base housing member 10having a threaded tubular bushing 12 extending therefrom for mountingthe same on a panel. A rotary operating shaft 14 extends through thebushing 12 for controlling the position of o the switch. A plurality ofswitch sections or decks I5 and 16 are shown mounted to the base member10 by a plurality of bolts 18. A cover plate 20 is provided after thelast switch section 16. It is to be pointed out that any number ofswitch decks, from I to 12 or more, can be used, with the deck 16 beingbroken away to indicate that additional decks can be used. The switch isshown enlarged in the drawing to better illustrate the structure. A24position switch as illustrated may have an outer diameter of about 1%inches, and the thickness of each switch deck is about one third of aninch.

FIG. 2 is a cross-section view of the switch of FIG. I, and FIG. 3 is anexploded perspective view showing such a switch with a single switchdeck. As shown in FIG. 2, the operating shaft 14 has a slot 22 in theend thereof into which an actuating blade 24 is keyed. The blade 24 isheld in position with an end thereof in the slot 22 by the cover plate20. The base member 10 of the switch forms a housing in which a detentmechanism 27 is positioned. This mechanism includes an elongated rotor(FIG. 3) with opposing holestherein in which springs 28 are positioned.The springs 28 force balls 30 outwardly against the wall 31 of thehousing recess 26, and has ribs thereon (FIG. 3) to form detentedpositions. The detent mechanism 27 is turned by the blade 24 as theswitch operating shaft 14 is rotated.

A stop plate 32 is also provided in the recess 26 in the base member 10.This plate is also keyed to the blade 24, and has a projecting stop arm33 which engages pins 34 in the base 10 to limit the rotary movement ofthe operating shaft 14. The pins 34 may be positioned in any desiredones of the openings 35 in the base 10, to limit the rotary movement ofthe shaft 14, as

may be required.

Each switch section or deck includes a cylindrical housing member 36which is molded of insulating material. This member has a plurality ofconductors 38 embedded therein which are substantially uniformlyradially positioned about the cylindrical housing 36. The conductorshave outwardly extending terminal portions 39 portions 40. The contactportions 40 may be bent upwardly to facilitate contact therewith by therotor, as will be further explained. On the top side of the insulator 36is an insulating cover plate 42, which has a recess 43 on the bottomside in which a common annular conductor 44 is placed. The conductor 44has a terminal projection 45 to which electrical connection can be made.

Positioned within the housing 36 is a rotor structure 48 including aninsulating member 49 having one or more contacts 50 movable thereby. Themember 49 has a slot for receiving the blade 24, with the operatingshaft 14 and the actuating blade 24 cooperating to form a rotaryactuator for the rotor structure 48.

As shown in FIGS. 2 and 4, the movable contact 50 is U- shaped and hasone arm selectively engaging the individual contacts 40 of theconductors 38 and another arm engaging the common conducting ring 44(FIG. 2). The movable contact 50 is made of a resilient metal to providespring biased engagement with the fixed contacts. It will be obviousthat a plurality of contacts 50 can be positioned in the recessesprovided in rotor 49 to simultaneously bridge a plurality of contacts 38to the common conductor 44.

An insulating disc 52 is positioned in the end of the cylindricalhousing member 36 opposite to that engaged by the cover plate 42. Thisdisc may have projections 54 about the periphery thereof which 36 to keythe same in position. The disc 52 has a plurality of ridges 56 (FIG. 5)which extend between the individual conand inwardly extending contactmate with recesses 55 in the member tact portions 40 to insure that thecontacts are insulated from each other. The ridges also provide a recessor well under each contact into which foreign material which may enter'the switch, or which produced by engagement of the contacts, can fall toeliminate the possibility of such material bridging thecontacts. Also,the top of the ridge extendingbetween adjacent contacts 40 may beengaged by the contact 50 as it moves from one contact portion 40 toanother, and can be molded of material with abrasive therein so that itcleans the engaging surface of the contactSO. It may be desirable tohave a smaller number of intercngagingprojections 54 and recesses 55than shown, it being only necessary to hold the disc 52 and the housingsection 36in radial alignment so that the ridges 55 are positionedbetween the individual contact portions 40. The insulating disc 52 has acenter opening 57 to receive a hub 51 on the rotary. insulating member49 of rotor structure 48, to hold the rotorstructure in axial alignment.

FIG. 5 shows in more detail the construction of the insulating disc 52and the ridges 56 thereon. The disc has a central hub portion .53, andthe ridges 56 extend from'this hub to the edge of the disc to engage theinsulator 36. Actually the ridges 56 continue to the projections 54which fit in the recesses 55 in the insulator 36. The space defined by apair of adjacent ridges, the hub portion 53 and the inside surface ofthe 'insula-' tor 36 forms a well under each contact into which foreignmaterial can drop, so that this is removed from'the contacts and doesnot provide a conducting bridge therebetween. As previously stated, thedisc 52 may be molded of material having abrasive in the portion thereofforming the ridges, and this acts to clean the surface of contact 50 asthis contact slides thereacross. However, this will produce-smallconducting particles which could form bridges between the contacts 40.FIG. 5 shows the contact 40 and the insulator 36 to showthe relativeposition of the contacts and wells formed by the ridges.

FIG. 6 shows the contact arrangement in more detail, and shows that anumber of contacts 50 may be used on the rotor 48. This figure alsoshows that the common conductor 44 may be replaced by a plurality offiat conductor segments. in the structure shown, six conductor segments61, 62, 63, 64, 65 and 66 are used in place of thesingle conductor 44.In this structure, a 24 position switch is illustrated having 24 fixedcontacts .40, so that there are four contacts 4D for each conductorsegment 61' to 66.'Six movable contacts 50 are provided in the rotor,one for each segment 61 to 66. The switch structure therefore providessix separateswitching sections, each having four positions in which adifferent one of the contacts 40 is connected to one of the contactconductor-61 to 66.

For such a switch, the stop pins 34 would be positioned to allow thestop arm 30 to move through an angle of 60, and the detent structure 27would clearly define the four positions in the 60 segment.

it will be apparent that various arrangements of the movable contactsand contact segments can be provided to provide desired switchingarrangements. Thus each deck can form a plurality of separate switchsections, and a plurality of decks can be used. Theswitch contactarrangement is extremely flexible and can provide a large number ofsimultaneously operated switching section in a very small switchstructure.

In the switch structure shown, the movable contact 50 engages a ridge 55as it moves from one contact portion 40 to another, and breaks the onecontact before thenext contact is made. It will be apparent that thecontact 50 can be constructed so that it will simultaneously engage twocontact portions, and the first contact is not broken until after thenext contact is made. In such case, the ridges 55 are constructed sothat the contact 50does not engage the tops thereof as it moves from onecontact portion 40 to the next.

The switch construction of the invention provides a very compact rotaryswitch having 16 or more rotary positions. One or more switch decks canbe provided to thereby provide a large number of switched connectionswhich can be independent of each other or have any one of a large numberof different relations as may be required for different applications.

I claim: I l. A rotary multi-position electrical switch structureincluding in combination,

a molded cylindrical insulating member having a plurality of conductorsmolded therein, said conductors being substantially uniformly radiallyspaced about said insulating member and having external terminalportions and internal contact portions,

an insulating plate engaging one end of said cylindrical insu-j latingmember, contact means in engagement with said insulating plate,

a rotor structure within said insulating member having a rotaryinsulating member and at least one conducting contact moved by saidmember, said contact having portions selectively engaging said contactportions of said conductors and said contact means, and

an insulating disc engaging said cylindrical insulating member at theend thereof opposite to said end engaging said insulating plate, saiddisc having a portion extending into said cylindrical insulating memberand ridges extending between said contact portions, said disc and saidcylindrical member having interengaging portions to .insure that saiddisc is in a predetermined radial position with respect to saidcylindrical member.

2. A switch structure in accordance with claim 1 wherein said internalcontact portions have raised ends, and said contact of said rotorstructure is U-shaped and has a first end adapted to selectively engagesaid contact portions and a second end adapted to engage said contactmeans.

3. A switch structure in accordance with claim 1 wherein said insulatingdisc extends within said cylindrical insulating member with one surfacethereof flush with said opposite end of said insulating member.

4. A switch structure in accordance with claim 1 wherein said ridges ofsaid insulating disc have heights to be engaged by said contact of saidrotary member when said contact moves from one of saidcontact portionsto another, and wherein said ridges are constructed of amaterial whichacts to clean said contact as said contact moves thereacross.

5. A switch structure in accordance with claim 4 wherein said insulatingdisc has a central hub connected to said ridges and cooperatingtherewith and with the inside surface of said cylindrical insulatingmember to form wells under said contact portions. I b v,

6. A switch structure in accordance with claim 1 wherein said insulatingplate has a plurality of recesses therein and said contactmeans includesa plurality of flat conductors positioned in said recesses, with eachconductor having a radial 8. A rotary electrical switch structureincluding in combination,

a base member having an operating shaft supported thereby and meanscoupled to said shaft providing predetermined switching positions,

a plurality of switch decks mounted on said base member each including acylindrical insulating housing section having a plurality of conductorsmolded therein in radially spaced positions, an insulating disc inpredetermined positional engagement with said housing section and havinga central opening therein, contact means supported in fixed positionwith respect to said conductors, and a rotor within said housing sectionincluding a movable contact selectively bridging said conductors andsaid contact means,- said rotor including a rotary insulating memberhaving a hub extending into said central opening in said insulatingdisc, and 7 drive means coupling said operating shaft to said rotor ofeach of said switch decks for simultaneously rotating the same.

tion of said operating shaft, with the extent of rotation beingdetermined by the positioning of said stop pins in said openings.

11. A rotary switch structure in accordance with claim 1 wherein saidinsulating disc has a central opening therein, and said rotaryinsulating member has a hub extending into said central opening.

I. I I 1 i

1. A rotary multi-position electrical switch structure including incombination, a molded cylindrical insulating member having a pluralityof conductors molded therein, said conductors being substantiallyuniformly radially spaced about said insulating member and havingexternal terminal portions and internal contact portions, an insulatingplate engaging one end of said cylindrical insulating member, contactmeans in engagement with said insulating plate, a rotor structure withinsaid insulating member having a rotary insulating member and at leastone conducting contact moved by said member, said contact havingportions selectively engaging said contact portions of said conductorsand said contact means, and an insulating disc engaging said cylindricalinsulating member at the end thereof opposite to said end engaging saidinsulating plate, said disc having a portion extending into saidcylindrical insulating member and ridges extending between said contactportions, said disc and said cylindrical member having interengagingportions to insure that said disc is in a predetermined radial positionwith respect to said cylindrical member.
 2. A switch structure inaccordance with claim 1 wherein said internal contact portions haveraised ends, and said contact of said rotor structure is U-shaped andhas a first end adapted to selectively engage said contact portions anda second end adapted to engage said contact means.
 3. A switch structurein accordance with claim 1 wherein said insulating disc extends withinsaid cylindrical insulating member with one surface thereof flush withsaid opposite end of said insulating member.
 4. A switch structure inaccordance with claim 1 wherein said ridges of said insulating disc haveheights to be engaged by said contact of said rotary member when saidcontact moves from one of said contact portions to another, and whereinsaid ridges are constructed of a material which acts to clean saidcontact as said contact moves thereacross.
 5. A switch structure inaccordance with claim 4 wherein said insulating disc has a central hubconnected to said ridges and cooperating therewith and with the insidesurface of said cylindrical insulating member to form wells under saidcontact portions.
 6. A switch structure in accordance with claim 1wherein said insulating plate has a plurality of recesses therein andsaid contact means includes a plurality of flat conductors positioned insaid recesses, with each conductor having a radial extent to be alignedwith a plurality of said contact poRtions.
 7. A switch structure inaccordance with claim 6 wherein said rotor structure has a plurality ofconducting contacts equal in number to the number of said flatconductors.
 8. A rotary electrical switch structure including incombination, a base member having an operating shaft supported therebyand means coupled to said shaft providing predetermined switchingpositions, a plurality of switch decks mounted on said base member eachincluding a cylindrical insulating housing section having a plurality ofconductors molded therein in radially spaced positions, an insulatingdisc in predetermined positional engagement with said housing sectionand having a central opening therein, contact means supported in fixedposition with respect to said conductors, and a rotor within saidhousing section including a movable contact selectively bridging saidconductors and said contact means, said rotor including a rotaryinsulating member having a hub extending into said central opening insaid insulating disc, and drive means coupling said operating shaft tosaid rotor of each of said switch decks for simultaneously rotating thesame.
 9. A switch structure in accordance with claim 8 wherein saidconductors have portions extending outside said cylindrical housingsection forming terminals, and portions extending within said housingsection forming fixed contacts which are engaged by said movable contactof said rotor.
 10. A switch structure in accordance with claim 8 whereinsaid base member has a plurality of openings therein and including apair of stop pins adapted to be positioned in said openings, and a stopplate coupled to said operating shaft having a stop arm adapted toengage said stop pins to limit rotation of said operating shaft, withthe extent of rotation being determined by the positioning of said stoppins in said openings.
 11. A rotary switch structure in accordance withclaim 1 wherein said insulating disc has a central opening therein, andsaid rotary insulating member has a hub extending into said centralopening.